Epitaxy of helical polyolefins: Polymer blends and polymer-nucleating agent systems

Helical polyolefins (polypropylene (PP) and poly(1-butene)) (PB-1) possess crystallographic faces in which the side-groups form well aligned rows. These structural features are shown, through a number of examples, to interact with linear polymers (polyethylene (PE) and polyamides) and nucleating agents. These interactions explain, on the basis of characteristic epitaxial relationships, the mutual activity of certain pairs of crystalline polymers and the hitherto puzzling “universality” of some nucleating agents towards both linear (i.e. PE-like) polymers and helical polyolefins.